Rectilinear electric switches



DeC. 6, 1966 M GERARDlN ET AL 3,290,471

RECTILINEAR ELECTRIC SWITCHES Filed Jan. l1, 1965 5 Sheets-Sheet l De- 6, 1966 M. GERARDIN ET A1. 3,290,471

REGTILINEAR ELECTRIC SWITCHES Filed Jan. l1, 1965 5 Sheets-Sheet 2 Dec. 6, 1966 M. GERARDIN ET A1- 3,290,471

RECTILINEAR ELECTRIC SWITCHES Filed Jan. 11, 1965 :5 sheets-sheet s United States Patent C) 3,290,471 RECTILINEAR ELECTRIC SWITCHES Maurice Gerardin, Meylan, Isere, France, and Jean Pelatan, 33 Rue Aristide Briand, Fontaine, Isere,

France Filed Ian. 11, 1965, Ser. No. 424,650 Claims priority, application France, Jan. 14, 1964, 960,185; Dec. 24, 1964, 999,878 6 Claims. (Cl. 200-161) This invention relates to electric switches of the rectilinear type comprising groups of fixed contact studs on which sliding contacts carried by a movable bar are adapted to slide, each slider providing an electrical connection between two adjacent contact studs of the corresponding group. The movements of translation of the movable bar may be controlled if desired by means of a pair of cables attached each to one end of said bar and adapted to be wound on a rotary drum controlled by means of a knob, this assembly constituting the control system of the switch.

In switches of this general type the fixed contact studs of the various groups are mounted as a rule on a fixed bar or rail of insulating material constituting a support therefor. However, in this case the fixed bar must have not yonly very reliable insulating properties, since it carries directly the fixed contact studs, but also very good mechanical properties since it constitutes the actual support of the assembly. Now these two requirements are generally rather diliicult to meet in a same member. Moreover, mounting the contact studs directly on the movable bar is most likely to reduce the mechanical strength of this bar.

In view of the foregoing it is the essential object of this invention to avoid these various drawbacks and to simplify the mounting of said fixed contact studs on a rectilinear switch of the type broadly set forth hereinabove. This invention is also concerned with a number of improvements in switches of this character and also to the means for controlling same.

To this end the present invention provides an electric switch of the rectilinear type comprising groups of fixed contact studs on which Contact sliders carried by a movable bar are adapted to slide under the control for example of a cable, this switch being characterized in that the fixed contact studs of the various groups are carried by separate blocks made from a material having very good electrical insulating properties, each block secured inside a common U-sectioned insulating support being adapted to carry a group of fixed contact studs and consisting preferably of a synthetic resin moulding in which one portion of the corresponding contact studs is embedded in order safely to anchor said Contact studs in the insulating block.

Other features and advantages of the electric switch of this invention will appear as the following description proceeds with reference to the accompanying drawings showing typical forms of embodiment thereof. In the drawings:

FIGURE 1 is a side elevational view with parts broken away showing a switch constructed according .to the teachings of this invention;

FIGURE 2 is a fragmentary sectional view taken upon the line II-II of FIGURE l;

FIGURE 3 is a perspective view showing the various component elements of each contact slider carried by the movable bar;

FIGURE 4 is a view partly in vertical section and partly in elevation of an alternate form of embodiment of the switch proper;

FIG'URE 5 is a cross-sectional view showing on a different scale the same form of embodiment;

ICC

FIGURE 6 is a perspective view showing one of the guide members provided at the ends of the support for guiding the control cable;

FIGURE 7 is a part-elevational, part-sectional view showing the switch control device;

FIGURE 8 is a fragmentary sectional view of the same device;

FIGURE 9 is an elevational and sectional view of an alternate form of embodiment of this device, and

FIGURE 1() is a plane view from above, with parts broke away, showing the actuating knob of the control device.

The switch illustrated in the drawings is adapted to be mounted inside the casing of a transformer for example of the type having its windings immersed in an oil bath. This switch may be mounted in this case on the upper wall 1 of the transformer casing.

This switch comprises a fixed bar 2 adapted to constitute a support for the different groups of stationary Contact studs 3a, 3b and 3c. However, all the studs of a same group are carried by a block of insulating material 4a, 4b and 4c respectively, and these blocks are secured in turn on the common support 2. In cross section this support 2 has the shape of a U and the blocks 4a, 4b and 4c are disposed between the two flanges 2a of this support.

Each block 4a, 4b and 4c is manufactured by moulding from a synthetic resin composition such as polyester resin having very good electrical insulating properties. More particularly, each block 4a, 4b and 4c has embedded therein the fixed contact studs of the corresponding group; to this end, a mould of adequate configuration is used, the studs being properly positioned in this mould prior to the moulding operation proper. Thus, the various contact studs are accurately positioned in the supporting block. Of course, this method is advantageous in that it eliminates the conventional steps necessary for securing the contact studs as well as the complementary fastening members which were used up to now.

Since the electrical insulation between the contact studs is ensured by the material constituting each supporting block 4a, 4b and 4c, the common support 2 of this assembly may be made from a material having poorer electrical insulating properties. In this case this support may be manufactured from a material having on the other hand very good mechanical properties. However, this support should consist of insulating material in order to insulate the various supporting blocks from one another. Thus, a suitable material for manufacturing this support 2 may consist of resin-impregnated cardboard, pressboard or the like.

Preferably, this support is so designed that its two flanges 2a have a certain elastic flexibility. Thus, the various blocks 4a, 4b and 4c may be secured therein by snappily engaging lateral caps S formed on either side of each block into corresponding holes 6 formed in said iianges 2a of support 2. In fact, the caps 5 may be inserted in these holes by momentarily divaricating the two flanges 2a of the support, whereafter these two anges are locked in their normal relative positions to avoid any undesired release of the supporting .blocks 4a, 4b and 4c. These flanges 2a may be locked in position by means of nuts 7 engaging screw-threaded shouldered portions of a pair of rods 8 acting as distance-pieces and bracing members, said portions extending through the flanges 2a of -the support. If desired, these rods 8 maybe used for securing the support 2 on the wall 1 of the transformer housing.

The fixed contact studs 3a, 3b and 3c of the switch extend towards the bottom of the U-sectioned support 2. Adjacent to this bottom is a movable bar 9 carrying the contact sliders 10a, 10b and 10c each adapted to co-act 3 with a corresponding group of iixed contact studs 3a, 3b and 3c, respectively.

The movements of translation of the movable bar 9 are controlled by means of a pair of 'cables 11 each anchored to one end of said bar and passing over guide members 13 secured on the ends of support 2. The other ends of these cables are attached to a winding drum 12 adapted to be rotated by means of an actuating knob 15, this assembly constituting the switch control device.

Each contact slider a, 10b and 10c comprises two jaws consisting of a pair of metal plates 18, 19 disposed on either side of a predetermined longitudinal position on said movable bar 9. On their inner faces of these two metal plates, a plurality of teeth 20 are formed; these teeth 20 are oset on one and the other plate so as to engage one another. On the other hand, these 'teeth are also adapted to engage notches 21 formed in the two edges of said movable bar 9. The two plates 18, `19 are thus retained in the desired longitudinal position on said movable bar 9.

' A spring 22 consisting of a metal blade of substantially U-shaped configuration is disposed straddlewise on each pair of plates 18, 19. The free edges 22a of these springs are bent and engage corresponding grooves 23 formed in the outer face of said plates 18, 19. Thus, these springs are adapted to hold these plates 18, 19 in their proper position after the springs themselves have been properly positioned.

The two plates 18, 19 comprise each a portion 24 extending beyond the corresponding longitudinal edge of the movable lbar 9. These two portions actually constitute the jaws of the corresponding contact slider. These jaws `are disposed on either side of the fixed contact studs 3a, 3b and 3c of the corresponding group. Due to the elastic pressure exerted by the springs 22 these jaws are resiliently clamped against the relevant contact studs.

Of course, the width of sliders 10a, 10b and 10c is such that each slider can simultaneously engage the two lixed contact studs of the corresponding group to provide the desired connections. These connections may be altered by moving the bar 9 longitudinally.

FIGURES 4 and 5 illustrate an alternate form of embodiment of the switch wherein the bar 9 has a specic conguratio-n with a view to reduce the overall length of the assembly. In fact, the two cables 11 are attached to a portion 9a of this bar which is shorter than its portion carrying the sliders 10a, 10b and 10c. An insulating sheath 16 covers each cable 11.

The members 13a provided at the ends of the insulating support 2 for guiding the cables are also so designed as to permit the delivery of the relevant cable at right angles to the cable portion contained in the fixed bar 2 but in different directions. To this end, each guide member consists of a tubular elbow having one end 13b pivotally mounted on a supporting plate 17. This plate 17 is adapted to be secured in the bottom of the insulating support 2 so as to extend at right angles to the flanges thereof, and is fomed with a pair of projections 17a adapted to engage recesses or holes formed in these flanges. In addition, this plate 17 is provided with an aperture in which the end portion 13b of said guide member 13 is pivotally mounted, the edge of this aperture engaging a groove 13d of this end portion 13b. The corresponding cable 11 will thus emerge from the opposite end 13C of the guide member which may be formed to this end with a slot 13e on its outer end.

Since the member 13a is adapted to pivot on the corresponding plate 17, the cable 11 may extend at right angles in diierent directions. Thus, the complete switchmay be mounted together with its control device in different positions, as required.

As Ialready set forth hereinabove this control device comprises a drum 12 on which the cables -11 are adapted to be wound. The spindle 14 of this drum 12 is rotatably mounted in a hollow member 30 acting as a support therefor, said spindle being also adapted to slide axially therein. This member 30 is mounted in a hole formed to this end in the wall 1 of the transformer casing and the end of spindle 14 which emerges therefrom carries the control knob 15.

The opposite end of said support 30 carries a strap 27 secured thereon for example by crimping or riveting. The side arms of this strap engage slideways provided in the corresponding side arms of another strap 26 disposed opposite said first strap 27. Both straps Iare assembled to constitute `a. kind of frame surrounding the drum 12.

Both cables 11 are slidably mounted in sheaths 25 bearing on the side arms of said straps 26, 27 by means of sheath end screw sockets 28. Each sheath end socket 28 engages one of a pair of holes provided to this end in the corresponding side arms of said straps, respectively. Under these conditions the lower strap 26 is held in its assembled condition with respect to the upper strap 27 which is secured in turn on the hollow support 30. A lock nut 29 engaging each screw socket 28 permits of adjusting the tension of each sheath 25.

The lower strap 26 carries a stop pin 32 adapted to engage a slot 33 formed in the lower peripheral portion of drum 12. Thus, the switch proper may be moved to dilterent positions with respect to this contr-ol device.

The lower end of the hollow support 30 comprises a flange 34 engaging the inner face of wall 1. This support 30 is fastened in position by means of a nut 35 screwed on its upper end, the necessary fluid tightness being ensured by means of a gasket 36. This gasket is compressed by a packing ring 37 clamped by said nut 35.

In the hollow support 30 a pair of O-rings 41 iitting on the surface of spindle 14 are provided and retained by ya spacer ring 42 and a circlip 43.

This control device comprises means for constantly indicating the position of the lcontrol knob and therefore of the switch. This indicator comprises a Washer 44 held against rotation with respect to the hollow support 30 and provided with Ian index-forming projection 45. The lower edge 46a of the skirt 46 at the lower end of knob 15 is formed with a plurality of notches 47 each adapted to be engaged b-y turns by said index projection according to the position of the control knob.

The washer 44 is locked against rotation by the engagement of a tooth 48- formed on its inner edge in a corresponding groove 49 of the fixed hollow support 30.

The packing ring 37 may be of a width suiiicient to constitute a convenient means for securing a protection cover 52 surrounding the complete control device, as shown in FIGURE 7. If this cover is not required the packing ring may consist of a ring 37a of relatively smaller diameter a's shown in FIGURE 8.

A spring 54 surrounding the Spindle 31 between its hollow support 30 and the drum 12 -constantly urges the spindle 31 and therefore the knob 15 towards the wall 1 of the transformer casing. Thus, due to the engagement of the index 45 in one of the notches 47 of skirt 46, the knob 15 is retained in the selected position.

To `rotate the knob 1S for moving the bar 9 of the switch in the desired direction, the operator simply pulls the knob 15 upwards against the elastic resistance of spring 54 to free the skirt 46y from the fixed index 45. By releasing the knob 15 in the selected position thus obtained the spring 54 urges said knob 15 downwards and a detent-positioning effect is thus achieved. Preferably, the outer face of the Iknob skirt 46 carries reference signs corresponding to the different switch positions obtained in the various angular positions of the control knob.

The various component elements of the switch of this invention may be assembled beforehand completely in the assembly workshop. Besides, the various adjustments may also be effected beforehand. The nal assembly consists simply. in inserting the hollow support 3l) into a hole formed on this end in the wall 1 which corresponds to the cover, lid or casing of a transformer. Then this support is simply locked in position by means of the nut 3S, whereafter the packing ring 40 and control knob are fitted in position.

The use of two straps 27, 26 to constitute the framelike member surrounding the drum facilitates considerably the assembly of the switch and its control device.

Finally, it may be noted that due to its speciiic features and notably the structure of the group of fixed contact studs on the one hand and the design of the sliding contacts or sliders on the other hand, the switch proper is attended by many advantageous features with respect to hitherto known rectilinear switches. In fact, this switch is particularly sturdy .and the various current-receiving component elements thereof are safely insulated from one another, the electrical connection between the fixed and movable contacts being on the other hand particularly eicient.

If desired, two identical switches may be actuated by means of a single control device by using a same and common drum 14. It is only necessary to modify the two straps 26, 27 so that two additional sheath end screw sockets such as 28 may be mounted thereon to permit the passage of the two cables controlling the second switch.

On the other hand, many modifications and variations may be brought to the specific forms of embodiment shown, described and suggested herein without departing from the spirit and scope of the invention as set forth in the appended claims.

What "we claim is:

1. An electric switch comprising a rectilinear insulating support which comprises two parallel walls forming a rectilinear groove, a plurality of groups of metal contact studs carried by said support, each one of said groups consisting of a block of insulating material having said lfixed contact studs embedded therein, said different blocks being secured between the two Walls of said support, a plurality of movable contacts carried by a movable bar, means for producing the movements of translation of said movable bar in a direction parallel to said xed insulating support, each movable contact being substantially U-shaped and adapted simultaneously to engage with its two side portions a pair of Said fixed contact studs in a same group thereof.

2. An electric switch as set forth in claim 1, wherein the parallel walls of said support have -a certain flexibility and said insulating blocks carrying the various groups of ixed contact studs are secured inside the groove formed by said walls by means of projecting caps formed on said blocks and snappily engageable in corresponding holes formed in said walls.

3. A rectilinear switch as set forth in claim 1, wherein the parallel walls of said support have a certain flexibility and said insulating blocks carrying the various groups of fixed contact studs are secured inside the groove formed by said walls by means of projecting caps formed on said blocks and engaging corresponding holes formed in said walls, each contact slider carried by said movable bar comprising two jaws consisting of a pair of metal plates disposed on either side of said bar and formed with teeth engaging corresponding notches formed in the longitudinal edges of said bar, a U-shaped spring engaged straddlewise on each pair of plates being adapted resiliently to urge the ends of said plates against said tixed contact studs.

4. A rectilinear Switch as set forth in claim 3, wherein a pair of control cables are each attached to one end of said movable bar, said cable passing over corresponding guide members carried by the ends of said xed rectilinear switch support, said guide members being of substantially elbow configuration and pivotally mounted on a base member secured in turn on said rectilinear switch support, said cables being wound on a common drum actuatable by means of a control knob.

5. A rectilinear switch las set forth in claim 3, wherein a pair of -control cables are attached each to one end of said movable bar, said cable passing over corresponding guide members carried by the ends of said rectilinear switch support, said guide members being of substantially elbow configuration and pivotally mounted on a base member secured in turn on said rectilinear switch support, said switch further comprising a control device comprising a drum on which said cables are adapted to be wound, said drum being carried by a rotary spindle mounted in a framelike assembly consisting of a pair of superimposed, oppositely-directed straps detachably assembled to each other.

6. A rectilinear switch as set forth in claim 5, wherein said control device further comprises means adapted to releasably lock said drum in each predetermined position thereof, said locking means consisting of a lock pin carried by the lower one of said pair of opposite straps in `which said drum is rotatably mounted, said lock pin being adapted to engage one of a plurality of peripheral notches formed in said drum, and means for indicating the position of said drum, said last-named means consisting of an external index carried by said drum supporting spindle.

References Cited by the Examiner UNITED STATES PATENTS 1,188,438 6/1916 Goldman et al.

1,189,116 6/1916 Johnson 200-16 2,249,976 7/ 1941 Penfold 20G-161 X 2,883,492 4/ 1959 Landers 200-16 X ROBERT K. SCHAEFER, Primary Examiner. H. HOHAUSER, Assistant Examiner. 

1. AN ELECTRIC SWITCH COMPRISING A RECTILINEAR INSULATING SUPPORT WHICH COMPRISES TWO PARALLEL WALLS FORMING A RECTILINEAR GROOVE, A PLURALITY OF GROUPS OF METAL CONTACT STUDS CARRIED BY SAID SUPPORT, EACH ONE OF SAID GROUPS CONSISTING OF A BLOCK OF INSULATING MATERIAL HAVING SAID FIXED CONTACT STUDS EMBEDDED THEREIN, SAID DIFFERENT BLOCKS BEING SECURED BETWEEN THE TWO WALLS OF SAID SUPPORT, A PLURALITY OF MOVABLE CONTACTS CARRIED BY A MOVABLE BAR, MEANS FOR PRODUCING THE MOVEMENTS OF TRANSLATION OF SAID MOVABLE BAR IN A DIRECTION PARALLEL TO SAID FIXED INSULATING SUPPORT, EACH MOVABLE CONTACT 